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<a href="#func-members">Functions</a> &#124;
<a href="#var-members">Variables</a>  </div>
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<div class="title">Real FFT Tables<div class="ingroups"><a class="el" href="group__RealFFT.html">Real FFT Functions</a></div></div>  </div>
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<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:ga70c20a29dce002df289426d5b4f67fa8"><td class="memItemLeft" align="right" valign="top">const <a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__RealFFT__Table.html#ga70c20a29dce002df289426d5b4f67fa8">__ALIGNED</a> (4)</td></tr>
<tr class="memdesc:ga70c20a29dce002df289426d5b4f67fa8"><td class="mdescLeft">&#160;</td><td class="mdescRight">Weights Table.  <a href="#ga70c20a29dce002df289426d5b4f67fa8">More...</a><br/></td></tr>
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Variables</h2></td></tr>
<tr class="memitem:ga8b1ad947c470596674fa3364e16045c6"><td class="memItemLeft" align="right" valign="top">const <a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__RealFFT__Table.html#ga8b1ad947c470596674fa3364e16045c6">realCoefA</a> [8192]</td></tr>
<tr class="separator:ga8b1ad947c470596674fa3364e16045c6"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:gac52f98b52a1f03bfac8b57a67ba07397"><td class="memItemLeft" align="right" valign="top">const <a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__RealFFT__Table.html#gac52f98b52a1f03bfac8b57a67ba07397">realCoefB</a> [8192]</td></tr>
<tr class="separator:gac52f98b52a1f03bfac8b57a67ba07397"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:gaf1592a6cf0504675205074a43c3728a2"><td class="memItemLeft" align="right" valign="top">const <a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__RealFFT__Table.html#gaf1592a6cf0504675205074a43c3728a2">realCoefAQ31</a> [8192]</td></tr>
<tr class="separator:gaf1592a6cf0504675205074a43c3728a2"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga1eb5745728a61c3715755f5d69a4a960"><td class="memItemLeft" align="right" valign="top">const <a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__RealFFT__Table.html#ga1eb5745728a61c3715755f5d69a4a960">realCoefBQ31</a> [8192]</td></tr>
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<a name="details" id="details"></a><h2 class="groupheader">Description</h2>
<h2 class="groupheader">Function Documentation</h2>
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          <td class="memname">const <a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a> __ALIGNED </td>
          <td>(</td>
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          <td class="paramname"></td><td>)</td>
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<p>Q15 table for reciprocal.</p>
<dl class="section user"><dt></dt><dd>Generation fixed-point realCoefAQ15 array in Q15 format: </dd></dl>
<dl class="section user"><dt></dt><dd>n = 4096 <pre>for (i = 0; i &lt; n; i++)
{
   pATable[2 * i]     = 0.5 * ( 1.0 - sin (2 * PI / (double) (2 * n) * (double) i));
   pATable[2 * i + 1] = 0.5 * (-1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}</pre> </dd></dl>
<dl class="section user"><dt></dt><dd>Convert to fixed point Q15 format round(pATable[i] * pow(2, 15))</dd></dl>
<dl class="section user"><dt></dt><dd>Generation of real_CoefB array: </dd></dl>
<dl class="section user"><dt></dt><dd>n = 4096 <pre>for (i = 0; i &lt; n; i++)
{
   pBTable[2 * i]     = 0.5 * (1.0 + sin (2 * PI / (double) (2 * n) * (double) i));
   pBTable[2 * i + 1] = 0.5 * (1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}</pre> </dd></dl>
<dl class="section user"><dt></dt><dd>Convert to fixed point Q15 format round(pBTable[i] * pow(2, 15))</dd></dl>
<dl class="section user"><dt></dt><dd>Weights tables are generated using the formula : <pre>weights[n] = e^(-j*n*pi/(2*N))</pre> </dd></dl>
<dl class="section user"><dt></dt><dd>C command to generate the table <pre>
for(i = 0; i&lt; N; i++)
{ 
  weights[(2*i)]   =  cos(i*c);
  weights[(2*i)+1] = -sin(i*c);
} </pre> </dd></dl>
<dl class="section user"><dt></dt><dd>where <code>N</code> is the Number of weights to be calculated and <code>c</code> is <code>pi/(2*N)</code> </dd></dl>
<dl class="section user"><dt></dt><dd>Converted the output to q15 format by multiplying with 2^31 and saturated if required. </dd></dl>
<dl class="section user"><dt></dt><dd>In the tables below the real and imaginary values are placed alternatively, hence the array length is <code>2*N</code>. </dd></dl>
<dl class="section user"><dt></dt><dd>cosFactor tables are generated using the formula : <pre> cos_factors[n] = 2 * cos((2n+1)*pi/(4*N)) </pre> </dd></dl>
<dl class="section user"><dt></dt><dd>C command to generate the table <pre>
for (i = 0; i&lt; N; i++)
{
  cos_factors[i] = 2 * cos((2*i+1)*c/2);
} </pre> </dd></dl>
<dl class="section user"><dt></dt><dd>where <code>N</code> is the number of factors to generate and <code>c</code> is <code>pi/(2*N)</code> </dd></dl>
<dl class="section user"><dt></dt><dd>Then converted to q15 format by multiplying with 2^31 and saturated if required.</dd></dl>
<p>end of DCT4_IDCT4_Table group </p>

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<h2 class="groupheader">Variable Documentation</h2>
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          <td class="memname">const <a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a> realCoefA[8192]</td>
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<dl class="section user"><dt></dt><dd>Generation of realCoefA array: </dd></dl>
<dl class="section user"><dt></dt><dd>n = 4096 <pre>for (i = 0; i &lt; n; i++)
{
   pATable[2 * i]     = 0.5 * ( 1.0 - sin (2 * PI / (double) (2 * n) * (double) i));
   pATable[2 * i + 1] = 0.5 * (-1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}</pre> </dd></dl>

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          <td class="memname">const <a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a> realCoefAQ31[8192]</td>
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<dl class="section user"><dt></dt><dd>Generation fixed-point realCoefAQ31 array in Q31 format: </dd></dl>
<dl class="section user"><dt></dt><dd>n = 4096 <pre>for (i = 0; i &lt; n; i++)
{
   pATable[2 * i]     = 0.5 * ( 1.0 - sin (2 * PI / (double) (2 * n) * (double) i));
   pATable[2 * i + 1] = 0.5 * (-1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}</pre> </dd></dl>
<dl class="section user"><dt></dt><dd>Convert to fixed point Q31 format round(pATable[i] * pow(2, 31)) </dd></dl>

</div>
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          <td class="memname">const <a class="el" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715">float32_t</a> realCoefB[8192]</td>
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<dl class="section user"><dt></dt><dd>Generation of realCoefB array: </dd></dl>
<dl class="section user"><dt></dt><dd>n = 4096 <pre>for (i = 0; i &lt; n; i++)
{
   pBTable[2 * i]     = 0.5 * (1.0 + sin (2 * PI / (double) (2 * n) * (double) i));
   pBTable[2 * i + 1] = 0.5 * (1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}</pre> </dd></dl>

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          <td class="memname">const <a class="el" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0">q31_t</a> realCoefBQ31[8192]</td>
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<dl class="section user"><dt></dt><dd>Generation of realCoefBQ31 array: </dd></dl>
<dl class="section user"><dt></dt><dd>n = 4096 <pre>for (i = 0; i &lt; n; i++)
{
   pBTable[2 * i]     = 0.5 * (1.0 + sin (2 * PI / (double) (2 * n) * (double) i));
   pBTable[2 * i + 1] = 0.5 * (1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
} </pre> </dd></dl>
<dl class="section user"><dt></dt><dd>Convert to fixed point Q31 format round(pBTable[i] * pow(2, 31)) </dd></dl>

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